The Oil-wet Ramp Test (commonly referred to as just the “Ramp test”) provides scores that are widely recognised by most designers from their R – rating results  R9, R10 etc.  The mechanism of achieving these results however is often poorly understood, as are the limitations of this test method.  There are very significant limitations to the ramp test and the creation of designs and specifications using ramp test results alone has lead to many problems for designers, their clients and indeed users and operators of facilities.

An investigation of slip resistance following an accident will almost certainly not involve the ramp test results, but rather will consider on-site pendulum testing.  It therefore follows that to design a floor without knowledge of the pendulum results of the floor surface selected is a significant risk.

A large part of recognising the ramp test’s limitations is obvious when the test method is explained. Approximately ½ a sqm of tiles to be tested is placed on a horizontal ramp panel, which is then inclined to the point where the test operator walking on it “slips”.  The steepness of the angle of the ramp panel is then measured and given a category rating from R9 to R13.

The following is a brief list of the limitations of the ramp test method:-

• Ramp angle results are simply a made-up number – they bear no correlation to the slope of a surface on which the tile can be used.
• The ramp test is not portable and can only be done in laboratory conditions
• The test shoes are a specific type of heavily profiled shoe and subject to the shoe manufacturers production and availability, which has caused problems over recent times
• Heavily profiled sole shoes may not reflect the footwear of the majority of users for the design application.
• Oil/water mix is the contaminant used on the test pieces, this may not reflect the conditions of the design application (i.e. will oil be present ?)
• A slip incident investigation will almost certainly involve conducting a pendulum test on-site. A ramp result used to make a design selection will carry little weight against a poor pendulum result conducted after a slip.
• There is no wear testing procedure or data bank following wear for the ramp test method
• Virtually all of the latest updates in the Australian Standards refer to pendulum testing methodology